Atomic Force Microscopy Reveals Liquids Adjust Viscosity When Confined, Shaken
Friday, May 2, 2008 - 11:35
in Physics & Chemistry
Getting ketchup out of the bottle isn't always easy. However, shaking the bottle before trying to pour allows the thick, gooey ketchup to flow more freely because it becomes more fluid when agitated. The opposite is not typically true -- a liquid such as water does not become a gel when shaken. New research shows that when water is confined to a small space, it behaves like a gel. Then, when shaken, it becomes fluidic and exhibits the same structural and mechanical properties as water in a bottle. The study -- the first to use an atomic force microscope to measure the viscosity of confined fluids -- revealed that these liquids can respond and modify their viscosity based on environmental changes.